As embedded systems continue to evolve, host-based processing is often offloaded to a co-processor dedicated for specific tasks in order to improve the performance and power utilization. In this the audio subsystem seems to be no exception and more vendors are trying to offload tasks to DSPs, be they embedded in SoCs or audio codecs. This evolution requires changes in ASoC to represent all the routing and processing capabilities of these DSPs.

The current efforts are based on two methods being propagated. The first approach developed by Liam Girdwoodand TI, typically referred to as soc-dsp aka dynamic PCM, introduces the notion of dynamic PCM nodes, where audio front-ends (FEs-classic PCM device visible to user) and audio back-ends (BEs-soc-hardware interfaces) represent audio links.

The second approach being discussed is referred as CODEC<-->CODEC model as proposed by Mark Brown, where the DSP is represented as another codec in the system and links to the real codec in the system through the machine map.

This talk takes a look at both the approaches and latest evolutions, future plans on these methods and discusses the common infrastructure needs which need to considered for making this representation an effective one for SoC and codec vendors